This ones going to run..on.. a....bit:

http://news.bbc.co.uk/1/hi/uk/6405051.stm

Adam

My mum's car is in the garage with the exact symptoms, would the engine
warning light come on though if the oxygen sensor had been damaged? Oxford
area...

"History" <yesindeedtomeplease (AT) ohyes (DOT) com> wrote

It didn't when I had a faulty sensor on my '94 BMW 525.
AFAIK it 'fine tunes' the fuel/air mixture, which affects the emissions and
fuel consumption.
My car failed the MOT on emissions, but after it was replaced it passed.
The thing is, that there was no noticeable difference in performance,
between before and after.
I can't see faulty Lamdas giving all the problems that have been reported.
Cars failing to start, coughing and spluttering, reverting to 'limp home
mode' etc.
Mike.

History <yesindeedtomeplease (AT) ohyes (DOT) com> wrote:
Almost always.
The O2 sensor determines how much fuel it needs to put in.
If that goes wrong, then once the ECU notices it's faulty, it reduces
the fuel drastically to a 'best guess' at 'lean but will sort of run'.

It's better to be lean than rich, as a rich mixture will rapidly destroy
and overheat the catalyst, maybe even causing more damage to the car.

Mike G <metier (AT) lycos (DOT) co.uk> wrote:
Some cars have multiple oxygen sensors.
Some have ECUs which have the 'default' limp-home mode relatively far
from the normal operating point of the car engine.
Others have it much closer.

Well its confirmed, oxygen sensor is clogged. On a related matter my
girlfriend was complaining of a bad smell coming from her car and running
hot few days ago. Hasn't driven it since. Haven't gotten hold of her yet but
my guess, 95% sure is she filled up at the same Tesco my mum did.

History wrote:
BBC news were reporting this afternoon that it was Tesco and Morrisons
outlets that were affected, but they seem to have stopped saying that
now, possibly the Tesco heavy mob lawyers have been in touch. Wouldnt
surprise me if it was a Tesco money saving excersise gone wrong.

Ian Stirling wrote:

As all tests from Tesco on damaged cars, fueling stations, tankers, to fuel
depots are negative so far, the suggestion now turns to the possibility of
petrol having accidentally been contaminated with diesel.

--
Lin Chung.
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"Lin Chung" <lin.chung (AT) the (DOT) Water.Margin.com> wrote

It would take quite a large percentage of diesel in petrol to cause the
problems being reported. Especially as it's affected older cars, as well as
those with more sophisticated electronics.
Mike.

Mike G wrote:


Yes, I am aware of that. That's why it's fascinating. This suggestion was
from an oil man in Manchester interviewed on BBC Radio 4 Ten O'clock News.
Eagerly awaiting further revelation...

--
Lin Chung.
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